Biologists Jen Lau and Jay Lennon's research has revealed that plants under stress have another option when trying to adapt to environmental stressors - they turn to the microbes in the soil for aid.

August 13, 2012

Soil microbes are impulsive. So much so that they help plants face the challenges of a rapidly changing climate.

Michigan State University (MSU) AgBioResearch biologists Jen Lau and Jay Lennon studied how plants and microbes work together to help plants survive the effects of global changes such as increased atmospheric CO2 concentrations, warmer temperatures and altered precipitation patterns. The results, which appeared in a recent issue of the Proceedings of the National Academy of Sciences, showed that microbes in the soil not only interact with plants -- they also prompt them to respond to environmental changes.

“We found that these changes in the plants happen primarily because of what global changes do to the belowground microbes rather than to the plant itself,” said Lau, who works at Kellogg Biological Station, an MSU AgBioResearch research center. “Drought stress affects microbes, and they, in turn, drive plants to flower earlier and help plants grow and reproduce when faced with drought.”

The team conducted a multigenerational experiment that manipulated environmental factors above- and below-ground and paid close attention to the interaction between the plants and microbes in the soil. Close examination of this interplay revealed some interesting results.

Researchers already knew that drought stress reduces plant growth and alters the plants’ life cycles. The team was surprised, though, to observe that the plants were slow to evolve and that microbes did most of the work to help these plants survive in new, drier environments. This happened because the microbes were quick to adapt to the changing environment.

This new aspect of the plant-microbe relationship shows that plants have an additional strategy for survival, Lau said.

“When faced with environmental change, plants may not be limited to traditional ‘adapt or migrate’ strategies,” she said. “Instead, they may also benefit from a third approach – interacting with complementary species, such as the diverse microbes found in the soil.”